The Dimming PIR Occupancy Sensor uses passive infrared technology to detect motion and then trigger instructions to control the lighting based on occupancy.

The product is targeted at industrial applications, including warehouses, distribution centers, and cold storage facilities. The device provides an energy saving solution by either turning the lighting off completely, or by reducing light levels based on parameters selected by the facility management. Nordic’s nRF52832 SoC provides the Bluetooth LE connectivity from the device to a user’s Bluetooth 4.0 (and later) smartphone for setup, configuration, and sensor adjustments including time delay, ambient light sensitivity, and motion detection range and sensitivity.

The Dimming PIR Occupancy Sensors employ Silvair’s Bluetooth Special Interest Group (SIG) qualified Bluetooth mesh protocol ‘Silvair Mesh’—running on the Nordic SoC—to support Bluetooth mesh networking between a large number of sensors and other control devices in an industrial lighting setting. Mesh networking allows devices to communicate with any other device with information relayed via other nodes if necessary and without recourse to a central hub device. Such a system enables extended range, flexibility, scalability and redundancy.The mesh networking employed by the McWong sensors relays specific dimming commands with low latency across the network, avoiding the complexity that comes with sending information to each individual sensor in turn. Nordic’s software architecture includes a clear separation between the Bluetooth LE RF protocol software and McWong’s application code—which incorporates the Silvair mesh software—easing development, testing and verification.

Rather than requiring costly and time-consuming hardwiring to a central location, the mesh network offers fast and flexible operations that can be continuously adjusted. The ability to broadcast operating parameters from a smartphone and easily update functionality also makes scalability easier for facility owners and operators.

The Dimming PIR Occupancy Sensor provides 360° of coverage at mounting heights up to 40 feet. The sensor also provides bi-level dimming via 0-10 V control, which complies with many energy code requirements and offers greater energy-efficient performance than simple on/off control. The IP65 rating makes the sensor ideal for wet locations, such as parking structures, nurseries or loading docks.

While some embedded systems do just fine with a single microcontroller, there are circumstances when offloading some processing into a second processing unit, such as a second MCU, offers a lot of advantages. In this article, Jeff explores this situation in the context of a robotic system project that uses Arduino and an external motor driver.

By Jeff Bachiochi

When your tasks begin to slip, it might be time to get help. At home, when the job jar begins to overflow, it’s often time to call in a professional to fix the leak, repaint, change the oil and so forth. At work, your project might require additional help from a programmer, purchaser, designer, or other specialist. I believe a good manager is one who is able to handle any facet of the project, but can also step back and let those associates handle their areas of expertise without micromanaging.

And so it is with programming a MCU. You can write the project yourself or—with confidence in your function library—you can make calls to complete a task without having to code those library functions. You can do more by having to do less. All that said, computationally intensive routines can eat up all your computing power. This might suggest that you move up to a more capable processor, or divide and conquer the project by using multiple MCUs.

Case in Point

I have a robot wheel base that uses an Arduino and an external motor driver board. The motors required more than the typical 2 A most Arduino motor shields can provide, so I went to an external motor driver for about $20. This requires direction and speed control outputs for each of the two motors. The wheel encoders require phase A and phase B inputs for each wheel.

It wasn’t long until the basic movement routines were written. Then I added encoder routines to handle measuring wheel movements. Finally, I made routines for adding acceleration/deceleration, positional and speed cooperation between the wheels. At that point, it was becoming clear that I was going to run out of processing power and application space. And I had not yet added a single sensor!

I considered using this Arduino as a separate processor just for wheel base movement. Certainly, someone must have integrated an MCU with motor drivers. Enter the motor controller. I chose to use a Basicmicro Roboclaw 2x7A motor controller (Figure 1) [1]. This is the smallest in a line of compatible controllers. At $70, it cost more than my motor driver. However, it incorporates the use of the wheel encoders, so it has some pretty good intelligence. It can handle two motors at 7 A of continuous current each. I like the fact that I can substitute other models should I need more current—up to 2 x 160 A!

While I plan to connect this via serial to the Arduino, it can be used stand-alone with an RC receiver, or with analog inputs from potentiometers. The serial link can be “simple” TX only or “packet” TX/RX to provide feedback.

Stall Current

Your motor (and gearing system) can produce some maximum torque or rotational force on a wheel to overcome the load or weight of the robot. Larger loads require more torque. Motors are rated by the maximum torque they can produce. The load or resistance to move must be less than the motor torque, or the motor will not be able to move the load. This is the stalled state of the motor, and will draw maximum current, the “stall state current.” Motor drivers must be able to withstand this current, or the driver will be destroyed trying to dissipate excess heat—not to mention overheating the motor.

Starting from a standstill will most likely require this current until movement has started. High currents while starting are typical but temporary. As the speed increases, the torque required goes down, and so does the current. With the load completely removed, the motor rotates at its maximum speed, requiring minimum current. You will typically see this “no-load” rating (no-load current vs. speed) for a motor. You may also see a continuous current rating. This will be much less than the stall current, and your motor selection should be based on the ability to provide the required torque to run continuously without exceeding the continuous current rating. This is assuming you will need to run continuously.

I’ve measured the stall current of my wheel assembly and found it to be around 5 A. The no-load current is 1 A. The calculated stall torque at the wheel is about 44 foot-pounds (ft-lb) of force after all the gearing. That may sound like a lot, but this robot carries three gel-cell batteries, and the batteries themselves are over 22 lbs. Besides the six motor/power connections, there are seven other control inputs. Two of these are relegated to the wheel encoders, and two are for the motor control mode. The last three are up for grabs, but have specific functions that you might need, depending on the control mode chosen. For instance, if you are using the controller for a remote control (RC) vehicle, you might want to use S3 for a flip input. This input reverses the direction controls when it detects that the vehicle has been flipped upside down, like in the Robot Wars TV show. …

Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.

Aetina announced a partnership to build an autonomous, solar-powered mobile robot with GPS tracking, sensors, and 6x HD cameras, based on its “AX710” carrier for the Linux-driven Jetson AGX Xavier.Taiwan-based Aetina and an undisclosed third party are developing the UGV (Unmanned Ground Vehicle) robot for border and shore patrol and other remote inspection and exploration applications. The robot will be built around Nvidia’s powerful, AI-enabled Jetson AGX Xavier module via Aetina’s new AX710 carrier board.

AX710, front and back(click images to enlarge)

We missed the AX710 when it was announced in February, but have detailed it farther below. The AX710, which follows Aetina’s earlier ACE-N310 carrier for the Jetson TX1/TX2/TX2i modules, joins CTI’s Rogue and Mimic Adapter carriers for the Xavier.

Nvidia’s 105 x 87 x 16mm Jetson AGX Xavier module has greater than 10x the energy efficiency and more than 20x the performance of the Jetson TX2, claims Nvidia. The module is equipped with 8x ARMv8.2 cores and a high-end, 512-core Nvidia Volta GPU with 64 tensor cores with 2x Nvidia Deep Learning Accelerator (DLA) engines. The Xavier is further equipped with a 7-way VLIW vision chip, as well as 16GB 256-bit LPDDR4 RAM and 32GB eMMC 5.1.

The upcoming UGV built around Aetina’s AX710 board will use the deep learning algorithms running on the Xavier to “understand and react to the surroundings” in real time based on camera and environmental sensor input, says Aetina. The company’s chief partner in the project will provide a GPS-based vehicle tracking system.

The robot will be equipped with solar panels. Their facing orientation will be continually adjusted to the best solar zenith angle calculated by the Xavier with the help of an optical sensor. Other sensors include thermal, infrared sensor, and metal detection sensors.

The UGV will be equipped with 6x Full HD, 360-degree cameras. Other features include LED lighting and the third-party, cloud-connected GPS tracking system, which features geofencing. The system will support up to 5G cellular connectivity as well as Innodisk’s iCAP remote monitoring system.

AX710 carrier

Like CTI’s Rogue carrier, Aetina’s compact, 112 x 107mm AX710 is designed to stack nicely with the 105 x 87 x 16mm Xavier module for deployment on robots and other space-constrained devices. Available with -25 to 80°C or -40 to 85℃ support with 10% to 90% humidity tolerance, the carrier board has a 9-20V DC input.

AX710 block diagram and Jetson AGX Xavier(click images to enlarge)

The AX710 carrier provides coastline ports including 2x HDMI, 2x USB 3.1, and single USB 3.1 Type-C and micro-USB ports. There’s also a GbE port via RJ45, as well as two more GbE ports via an extension adapter.

AX710 portside view

The AX710 is equipped with 2x CANBus, 2x UART, 5x GPIO, and single RS-232, I2C, and “front panel” interfaces. There are also 4x I-PEX connectors, as well as M.2 M-Key and M.2 E-Key slots.

The board also provides a 60-pin extension slot. It’s unclear if that is the source of the MIPI-CSI-2 connections for Aetina’s optional camera modules. Although the robot will offer 6x HD cameras, the AX710 supports up to 8x HD cams. Alternatively, you can have 4x 4K cameras or an undisclosed number of GSML/FPD-LINK III SerDes(PDF) cameras.

The AX710 is available with an “iNAVI” optimization service featuring an embedded OS based on Linux, including secure boot and system recovery features. Aetina pre-integrates the necessary driver porting and and can customize OS specifications. Other technical services are also available.

Further information

No ship date or name was listed for the upcoming AX710-based UGV. Aetina Corporation will share a booth with its UGV partner at DSEI (Defence & Security Equipment International) at the Exhibition Centre London UK (EXCEL) from Sep. 10-13 at booth S4-205.

The AX710 carrier board appears to be available at an undisclosed price. More information may be found on Aetina’s AX710 product page.

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Analog & Power. (9/3) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AC-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch (9/10) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

Maxim Integrated Products has announced a pair of sensors. The MAX30208 is a clinical-grade digital temperature sensor that enables new wearable health and fitness use cases at half the power. And the MAXM86161 Is an in-ear heart-rate monitor provides best-in-class SNR at lowest power and 40% less space for continuous heart-rate and SpO2 measurements, according to Maxim.

To provide value, wearable health and fitness monitors require greater accuracy in measuring human biometrics such as body temperature and heart rate, but device designers have been limited by sensor accuracy for small, battery-powered, body-worn devices. Maxim’s two new continuous-monitoring body sensors provide higher degrees of accuracy in measuring vital signs such as temperature, heart rate and blood-oxygen saturation (SpO2).The MAXM86161 in-ear heart-rate monitor and pulse oximeter is the market’s smallest fully integrated solution that delivers highly accurate heart-rate and SpO2 measurements from hearables and other wearable applications. It is optimized for in-ear applications with its industry-leading small package size (40 percent less than the closest competitor) and best-in-class SNR (3dB improvement with band limiting signal for PPG use cases compared to closest competitor). This enables development of devices that cover a wider range of use cases. MAXM86161 delivers approximately 35 percent lower power to extend battery life of wearables. In addition, an integrated analog front-end (AFE) eliminates the additional AFE typically needed to procure a separate chip and connect to the optical module.

The MAX30208 digital temperature sensor delivers clinical-grade temperature measurement accuracy (±0.1°C) with fast response time to changes in temperature. It also meets the power and size demands of small, battery-powered applications such as smartwatches and medical patches. It simplifies the design of battery-powered, temperature-sensing wearable healthcare applications. Easier to use than competitive offerings, it measures temperature at the top of the device and does not suffer from thermal self-heating like competitive solutions. MAX30208 is compatible with up to four I2C addresses to enable multiple sensors on the same IC bus. The MAX30208 can be attached to either a PCB or a flex printed circuit (FPC).

To extend battery life of wearables, the MAXM86161 consumes approximately 35 percent lower power versus the closest competitor, with less than 10 μA operating power (typical at 25sps) and 1.6μA in shutdown mode. Compared to the closest competitive solution, the MAX30208 consumes only half the power (67 μA operating current during active conversion vs. 135 μA) under a representative use case.

MAXM86161 is available in an OLGA package (2.9 mm × 4. 3mm × 1.4 mm), which is 40 percent smaller than the closest competitor. MAXM86161 includes three LEDs—red and infrared for SpO2 measurement and green for heart rate; MAX30208 is available in a 10-pin thin LGA package (2 mm × 2 mm × 0.75 mm).

The MAXM86161 is available at Maxim’s website for $4.41 (1000-up, FOB USA); also available from authorized distributors; The MAXM86161EVSYS# evaluation kit is available for $150

The MAX30208 is available at Maxim’s website for $1.25 (1000-up, FOB USA); also available from authorized distributors; The MAX30208EVSYS# evaluation kit is available for $56

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Embedded Boards.(8/27) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Analog & Power. (9/3) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AC-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch (9/10) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

The September issue of Circuit Cellar magazine is out next week! This 84-page publication stitches together a fine tapestry of fascinating embedded electronics articles crafted for your reading pleasure.

Security Solutions for IoTBy Jeff ChildIn this IoT era of connected devices, microcontrollers have begun taking on new roles and gaining new capabilities revolving around embedded security. MCUs are embedding ever-more sophisticated security features into their devices-both on their own and via partnerships with security specialists. Here, Circuit Cellar’s Editor-in-Chief, Jeff Child, looks at the latest technology and trends in MCU security.

Electromagnetic Fault Injection: A Closer Look

By Colin O’Flynn

Electromagnetic Fault Injection (EMFI) is a powerful method of inserting faults into embedded devices, but what does this give us? In this article, Colin dives into a little more detail of what sort of effects EMFI has on real devices, and expands upon a few previous articles to demonstrate some attacks on new devices.

Product Focus: IoT Gateways

By Jeff Child

IoT gateways are a smart choice to facilitate bidirectional communication between IoT field devices and the cloud. Gateways also provide local processing and storage capabilities for offline services as well as near real-time management and control of edge devices. This Product Focus section updates readers on these technology trends and provides a product gallery of representative IoT gateways.

Comparing Color Sensor ICs

By Kevin Jensen

Driven by demands from mobile phone, display and specialty lighting equipment manufacturers, the need for sophisticated and accurate chip-scale color and spectral sensors has become stronger than ever. In this article, ams’ Kevin Jensen describes the types of optical sensors and detectors. He also provides ideas on evaluating the suitability of each type for specific applications.

PC-BASED SOLUTIONS FOR EMBEDDED SYSTEMS

Mini-ITX, Pico-ITX and Nano-ITX Boards

By Jeff Child

Products based on the various small-sized versions of the ITX form factor—Mini-ITX, Pico-ITX and Nano—ITX-provide system developers with complete PC-functionality and advanced graphics. Circuit Cellar Chief Editor Jeff Child explores the latest technology trends and product developments in these three ITX architectures.

Using Small PCs in New Ways

By Wolfgang Matthes

Even simple MCU-based projects often require some sort of front panel interface. Traditionally such systems had to rely on LEDs and switches for such simple interfaces. These days however, you can buy small, inexpensive computing devices such as mini-PCs and notebook computers and adapt them to fill those interfacing roles. In this article, Wolfgang steps you through the options and issues involved in connecting such PC-based devices to an MCU-based environment.

FOCUS ON MICROCONTROLLERS

Guitar Game Uses PIC32 MCU

By Brian Dempsey, Katarina Martucci and Liam Patterson

Guitar Hero has been an extremely popular game for decades. Many college kids today who played it when they were kids still enjoy playing it today. These three Cornell students are just such fans. Learn how they used Microchip’s microcontroller and 12-bit DAC to craft their own version that lets them play any song they wish by using MIDI files.

Offloading Intelligence

By Jeff Bachiochi

While some embedded systems do just fine with a single microcontroller, there are situations when offloading some processing into a second processing unit, such as a second MCU, offers a lot of advantages. In this article, Jeff explores this question in the context of a robotic system project that uses Arduino and an external motor driver.

Building a Portable Game Console

By Juan Joel Albrecht and Leandro Dorta Duque

32-bit MCUs can do so much these days—even providing all the needed control functionality for a gaming console. Along just those lines, learn how these three Cornell students built a portable game console that combines a Microchip PIC32 MCU embedded in a custom-designed 3D-printed case, printed circuit board and in-house gameplay graphics. The device includes a 320 x 240 TFT color display.

… AND MORE FROM OUR EXPERT COLUMNISTS

Variable Frequency Drive Part 2

By Brian Millier

In Part 1 Brian started to describe the process he used to convert a 3-phase motor and OEM Variable Frequency Drive (VFD) controller—salvaged from his defunct clothes washer—into a variable speed drive for his bandsaw. In this article, he completes the discussion this tim,e covering the Cypress Semi PSoC5LP SoC he used, the software design and more.

Semiconductor Fundamentals Part 1

By George Novacek

Embedded systems—or even modern electronics in general—couldn’t exist without semiconductor technology. In this new article series, George delves into the fundamentals of semiconductors. In Part 1 George examines the math, chemistry and materials science that are fundamental to semiconductors with a look at the basic structures that make them work.

Atmosphere and Radio Bridge have announced a partnership that integrates Radio Bridge sensors with Atmosphere’s cloud-based IoT platform for rapid deployment and management of several sensor technologies across multiple low-power wide area networks. An integrated solution was recently deployed for a customer that manages disaster response in the energy industry. The solution was built on the Atmosphere Platform to connect and manage hundreds of Radio Bridge wireless sensors using a combination of Sigfox and LoRaWAN technologies.

Radio Bridge Inc. designs and manufactures long-range wireless sensors for the Internet of Things (IoT) industry using emerging wireless standards such as LoRaWAN and Sigfox. The entire portfolio of sensors products are designed for very long range, low cost, and extended battery life. The sensors are targeted toward the home security, smart city, medical device and industrial automation industries. Radio Bridge offers an optional web-based console for provisioning, monitoring, and configuration of the sensors in the field. Custom design is also available with the goal of achieving seamless sensor-to-cloud solutions for a variety of applications.

We have a BONUS newsletter for you this week: PCB Design Tools! The process of PCB design is always facing new complexities. Rules-based autorouting, chips with higher lead counts and higher speed interconnections are just a few of the challenges forcing PCB design software to keep pace. This newsletter updates you on the latest happenings in this area.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Analog & Power. (8/6) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AC-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch (8/13) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

July has a 5th Tuesday . That’s means we’re giving you an extra Newsletter: PCB Design! (7/30) The process of PCB design is always facing new complexities. Rules-based autorouting, chips with higher lead counts and higher speed interconnections are just a few of the challenges forcing PCB design software to keep pace. This newsletter updates you on the latest happenings in this area.

Analog & Power. (8/6) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AC-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch (8/13) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Embedded Boards.(7/23) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Analog & Power. (8/6) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AC-DC converters, power supplies, op amps, batteries and more.

July has a 5th Tuesday . That’s means we’re giving you an extra Newsletter: PCB Design! (7/30) The process of PCB design is always facing new complexities. Rules-based autorouting, chips with higher lead counts and higher speed interconnections are just a few of the challenges forcing PCB design software to keep pace. This newsletter updates you on the latest happenings in this area.

Microcontroller Watch (8/13) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

MCUs for Driverless CarsBy Jeff ChildDriverless cars are steadily advancing toward becoming a mainstream phenomenon. Building toward that goal, chip vendors are evolving their driver assistance technologies into complete driver replacement solutions. These solutions make use of powerful microcontroller solutions to analyze a car’s surroundings, process the information and employ control functionality to steer cars safely. Circuit Cellar Chief Editor Jeff Child examines the MCU technology and product trends that are key to driverless vehicle evolution.

Product Focus: Small and Tiny Embedded BoardsBy Jeff ChildAn amazing amount of computing functionality can be squeezed on to a small form factor board these days. These small—and even tiny—board-level products meet the needs of applications where extremely low SWaP (size, weight and power) beats all other demands. This Product Focus section updates readers on this technology trend and provides a product album of representative small and tiny embedded boards.

Portable Digital SynthesizerBy T.J. Hurd and Ben RobergeGone are the days when even a basic music synthesizer was a bulky system requiring highly specialized design knowledge. These two Cornell students developed a portable musical synthesizer using a Microchip PIC32 MCU. The portable system performs digital audio synthesis on the fly and produces sounds that range from simple sine waves to heavily modulated waveforms.

Displays for Embedded SystemsBy Jeff ChildThanks to advances in displays and innovations in graphics ICs, embedded systems can now routinely feature sophisticated graphical user interfaces. What used to require a dedicated board-level graphics/video board, now can be integrated into a chip or just a part of a chip. Circuit Cellar Chief Editor Jeff Child dives into the latest technology trends and product developments in displays for embedded systems.

Building a Twitter Emote RobotBy Ian Kranz, Nikhil Dhawan and Sofya CalvinSocial media is so pervasive these days that it’s hard to image life without it. But digital interactions can be isolating because the physical feedback component gets lost. Using PIC32 MCU technology, these three Cornell students built an emotionally expressive robot which physically reacts to tweets in a live setting. Users can tweet to the robot’s Twitter account and receive near instant feedback as the robot shares its feelings about the tweet via physical means such as sounds, facial expressions and more.

Understanding the Role of Inference Engines in AIBy Geoff Tate, Flex LogixArtificial Intelligence offers huge benefits for embedded systems. But implementing AI well requires making smart technology choices, especially when it comes to selected a neural inferencing engine. In this article, Flex Logix CEO Geoff Tate explains what inferencing is, how it plays into AI and how embedded system designers can make sure they are using the right solution for their AI processing.

FUN WITH LIGHT AND HEAT

Watt’s Up with LEDs?By Jeff BachiochiWhen Jeff puts his mind to a technology topic, he goes in deep. In this article, he explores all aspects of LED lighting—including the history, math, science and technology of LEDs. He discusses everything from temperature issues to powering LEDs. After purchasing some LEDs, Jeff embarks on a series of tests and shares his results and insights.

Automating the Art of ToastBy Michael Xiao and Katie BradfordThe emergence of culinary robotics and automation has already begun to revolutionize the way we prepare our meals. In this article, learn how these two Cornell undergraduates designed an advanced toaster that’s able to toast any pattern—image, text or even today’s weather—onto a piece of bread. The project makes use of Microchip’s MIC32 MCU and a Raspberry Pi Zero W board.

Build an RGB LED ControllerBy Dirceu R. Rodrigues Jr.There are a lot of fun and interesting things you can do with LEDs and different ways to control them. In this article, Dirceu describes an alternative approach to control RGB LEDs using the parallel FET dimming technique. He steps through his efforts to design and build an alternative lightning system based on power RGB LEDs. To control them he goes very old school and uses an 8-bit MCU and the BASIC programming language.

… AND MORE FROM OUR EXPERT COLUMNISTS

Energy Monitoring Part 3By George NovacekThis is the final installment of George’s energy monitoring article series. He discussed the solar power supply in Part 1 and the utility power data acquisition in Part 2. In Part 3, he wraps up the series by looking at the remaining modules that comprise his home energy monitoring setup, including the sensors, the natural gas monitor and the real-time clock.

The Fundamentals of FuseologyBy Robert LacosteJust because an electronic device is simple you shouldn’t relegate it to an afterthought in your embedded system design. Such is the case with fuses. Robert explores the fundamentals of this seemingly simple device. In this article, he dives into the history, key specifications and technology of fuses. He also steps you through an experiment to analyze the performance of fuses and shares his results.

Bluetooth Mesh (Part 4)By Bob JapengaIn this next part of his article series on Bluetooth mesh, Bob looks at how models are defined in the Bluetooth Mesh specification and how practical it is to use them. He looks at the models defined by the Bluetooth SIG and discusses creating your own models for Bluetooth Mesh.

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Analog & Power. (7/2) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AC-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch (7/9) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Embedded Boards.(6/25) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Analog & Power. (7/2) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch (7/9) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

The July issue of Circuit Cellar magazine is out next week! This 84-page publication will make a satisfying thud sound when it lands on your desk and it’s crammed full of excellent embedded electronics articles prepared for you.

Product Focus:IoT Interface Modules
The fast growing IoT phenomenon is driving demand for highly integrated modules designed for the IoT edge. Feeding those needs, a new crop of IoT modules have emerged that offer pre-certified solutions that are ready to use. This Product Focus section updates readers on this technology trend and provides a product album of representative IoT modules.

Macros for AVR Assembler Programming
The AVR microcontroller instruction set provides a simplicity that makes it good for learning the root principles of machine programming. There’s also a rich set of macros available for the AVR that ease assembler-level programming. In this article, Wolfgang Matthes steps you through these principles, with the goal of helping programmers “think low-level, write high-level” when they approach embedded systems software development.

Inrush Current Limiters in Action
At the moment a high-power system is switched on, high loads can result in serious damage—even when the extra load is only for short time. Inrush current limiters (ICLs) can help prevent these issues. In this article, TDK Electronics’ Matt Reynolds examines ICLs based on NTC and PTC thermistors, discussing the underlying technology and the device options.

A Look at Cores with TrustZone-M
It’s not so easy to keep up with all the new security features on the latest and greatest embedded processors—especially while you’re busy focusing on the more fundamental and unique aspects of your design. In this article, Colin O’Flynn helps out by examining the new processor cores using TrustZone-M, a feature that helps you secure even low-cost and lower power system designs.

PROJECTS THAT REUSE & RECYCLE

Energy Monitoring Part 2
In Part 1 of this article series, George Novacek began describing an MCU-based system he built to monitor his household energy. Here, he continues that discussion, this time focusing on the electrical power tracking module. As the story shows, he stuck to a design challenge of building the system with as many components he already had in his component bins.

Variable Frequency Drive Part 1
Modern appliances claim to be more efficient, but they’re certainly not designed to last as long as older models. In this project article, Brian Millier describes how he reused subsystems from a defunct modern washing machine to power his bandsaw. The effort provides valuable insights on how to make use of the complete 3-phase Variable Frequency Drive (VFD) borrowed from the washing machine.

FUN PROJECT ARTICLES WITH ALL THE DETAILS

Windless Wind Chimes (Part 2)
In part 1 of this article series, Jeff Bachiochi built a system to simulate breezes randomly playing the sounds of suspended wind chimes. In part 2 the effort evolves into a less random, more orchestrated project. Jeff decided this time to craft a string of chromatically tuned chimes, similar to what an orchestra might use so the project could be used to play music. The project relies on MIDI, an industry standard music technology protocol designed to create and share music and artistic works.

Building a Smart Frying Pan
There’s almost no limit to what an MCU can be used for—-including objects that previously had no electronics at all. In this article, learn how Cornell University graduate Joseph Dwyer build a Microchip PIC32 MCU-based system that wirelessly measures and controls the temperature of a pan on a stove. The system improves both the safety and reliability of cooking on the stove, and has potentially interesting commercial applications.

EOG-Controlled Video Game
There’s much be to learned about how electronics can interact with biological signals—not only to record, but also to see how they can be used as inputs for control applications. With ongoing research in fields such as virtual reality and prosthetics, new systems are being developed to interpret different types of signals for practical applications. Learn how Cornell graduates Eric Cole, Evan Mok and Alex Huang use electrooculography (EOG) to control a simple video game by measuring eye movement.